ONE ENGINE / EVERY INTERFACE

Bring the whole
workspace with you.

The same public methods power the browser studio, the calculation API and the MCP tools. Sources, assumptions and limitations travel with the result.

OPENAPI 3.1

Build with the API

Discover input contracts, run calculations and compare up to eight scenarios. No contact details or stored applications.

Open the API specification ↗STREAMABLE HTTP MCP

Connect an assistant

Calculation tools, source-linked answers, national benchmarks and complete guide resources.

Connection details ↗CANONICAL METHODS

Start with the studio

Use every method locally, save comparisons on your own device and download transparent schedules.

Open the universal studio ↗

REST quick start

POST numerical inputs to https://bostoninterestrates.com/api/v1/calculate with Content-Type application/json. Discover every required field at the calculator catalog. Example values below are illustrative.

{
  "toolId": "mortgage-payment",
  "inputs": {
    "price": 450000,
    "down": 90000,
    "rate": 6.5,
    "years": 30,
    "tax": 4500,
    "insurance": 1800,
    "hoa": 0,
    "pmi": 0,
    "extra": 0
  }
}

POST an object with a scenarios array of one to eight labeled scenarios to /api/v1/compare. Every response retains its own method and limitations. Invalid inputs return 422; malformed JSON 400; oversized bodies 413; incorrect content type 415. Calculation responses are not cached by this application.

MCP connection

Server URL: https://bostoninterestrates.com/api/mcp. Add it to an MCP-compatible client as a public Streamable HTTP server. No account is required for these public educational tools. A client connection is not presumed until that client completes its own setup.

Discover 34 calculation tools, national benchmarks, source-linked answers, portal discovery, private lending research and local property plans. Resources expose calculator contracts and complete published guides. All tools are read-only and do not contact a broker, save a lead or send a message.

Privacy and operational limits

Use numerical scenario inputs only. Do not send identity, account, credit-report or contact details. The API processes requests to return results; the browser studio computes locally instead. Hosting security logs may record connection metadata. Requests are bounded to 64 KiB and scenario comparisons to eight. Individual loan amortizations run for up to 600 months; a HELOC can include an additional draw phase. This public API is for education and integration testing; no paid API quota, uptime guarantee or private lender feed is represented.

Local planning API

GET https://bostoninterestrates.com/api/v1/portals/{domain}/local-plan to read a geographic edition’s source-linked decision file. An optional state=CA selects property-state references for an unassigned edition; it never assigns its permanent identity or fills financial assumptions. National specialist editions have no geographic plan. Independent editions expose only their own place file.

Discovery

Portal profiles · Source-linked answer example · Dated mortgage benchmarks · Machine-readable guide · Methods and disclosures.

Bring the wholeworkspace with you.